使用JSP+Servlet+MySQL实现登录注册功能

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🥭本文内容：使用JSP+Servlet+MySQL实现登录注册功能
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1.前言

大家好，我是Leo哥🫣🫣🫣，前几天一个在大学的粉丝跟我说：Leo哥，我们最近要搞那个Java期末作业，要求是通过Javaweb知识点，使用JDBC，MySQL，JSP,Servlet等技术实现一个登录和注册功能，能不能出一期教程啊，老师啥也不教。听到这里我也是感触颇深，让我看到我之前的影子，当时老师也是啥都不教，就念个PPT，啥都要咱们自己琢磨。既然这样，咱们就出一期保姆级教程。后面也会出一些demo案例放到这个系列，第一期就先来点简单的开胃菜吧好了，话不多说让我们开始吧😎😎😎。

2.环境配置

首先Leo哥这里先声明一下本次教程的环境配置哈，大家可以跟我横向对比。

因为是比较基础的一篇，考虑到做期末作业，没有接触到Maven，所以我们这里就还是使用原生jar包的方式哈。

环境:

Intellij IDEA 2023
MySQL8.0
Tomcat 8.5
JDK8
JDBC
Navicat 16

3.项目创建

首先我会带大家从零创建一个JavaWeb项目，然后进行环境测试没问题之后，我们再继续往下进行。

打开IDEA，File — New — Project进行创建

开始创建项目，这里我们直接进模块创建。

查看我们的项目结构，并引入MySQL依赖

添加Tomcat依赖

配置Tomcat服务器

首先点击IDEA，最上面，点击Edit Configuration进行配置

然后依次按照我图中点击即可。

然后依次点击选择自己的Artifacts进行配置。

首先第一步检查配置一下自己本地的Tomcat路径，没问题之后，然后选择我们项目的访问路径，最后点击apply。

最后我们启动项目，如果能访问到默认的JSP页面，说明我们项目环境搭建成功了。

欧克，我们环境搭建篇大功告成!!!

4.数据库准备

4.1 SQL建表语句

大家可通过自行创建SQL表

DROPTABLEIFEXISTS`user`;CREATETABLE`user`(`id`int(10)unsignedNOTNULLAUTO_INCREMENT,`username`varchar(50)NOTNULLDEFAULT'default',`password`varchar(50)NOTNULLDEFAULT'123456',`phone`varchar(50)NOTNULL,PRIMARYKEY(`id`))ENGINE=InnoDBAUTO_INCREMENT=4DEFAULTCHARSET=latin1;

4.2 插入数据

INSERTINTO`user`VALUES(1,'jack','19978786751','123456');INSERTINTO`user`VALUES(2,'tony','19975067512','123123');INSERTINTO`user`VALUES(3,'lisa','19971286751','123123');

5.编写后端代码

5.1 代码及项目结构总览

5.2 编写实体类

packageorg.javatop.case01.domain;/**
 * @author : Leo
 * @version 1.0
 * @date 2023-11-28 20:57
 * @description :
 */publicclassUser{privateint id;privateString username;privateString password;privateString phone;publicUser(int id,String username,String password,String phone){this.id = id;this.username = username;this.password = password;this.phone = phone;}publicStringgetPhone(){return phone;}publicvoidsetPhone(String phone){this.phone = phone;}publicUser(){}publicintgetId(){return id;}publicvoidsetId(int id){this.id = id;}publicStringgetUsername(){return username;}publicvoidsetUsername(String username){this.username = username;}publicStringgetPassword(){return password;}publicvoidsetPassword(String password){this.password = password;}@OverridepublicStringtoString(){return"User{"+"id="+ id +", username='"+ username +'\''+", password='"+ password +'\''+", phone='"+ phone +'\''+'}';}}

5.3 编写Dao接口

packageorg.javatop.case01.dao;importorg.javatop.case01.domain.User;/**
 * @author : Leo
 * @version 1.0
 * @date 2023-11-28 20:59
 * @description :
 */publicinterfaceUserDao{// 登录Userlogin(String username,String password);// 注册Booleanregister(User user);}

5.4 编写Dao实现类

packageorg.javatop.case01.dao.impl;importorg.javatop.case01.dao.UserDao;importorg.javatop.case01.domain.User;importorg.javatop.case01.utils.JdbcUtil;importjava.sql.Connection;importjava.sql.PreparedStatement;importjava.sql.ResultSet;/**
 * @author : Leo
 * @version 1.0
 * @date 2023-11-28 21:01
 * @description :
 */publicclassUserDaoImplimplementsUserDao{@OverridepublicUserlogin(String username,String password){User user =null;Connection connection =null;PreparedStatement preparedStatement =null;ResultSet resultSet =null;try{
            connection =JdbcUtil.getConnection();String sql ="select * from user where username = ? and password= ?";
            preparedStatement = connection.prepareStatement(sql);
            preparedStatement.setString(1, username);
            preparedStatement.setString(2, password);
            resultSet = preparedStatement.executeQuery();if(resultSet.next()){
                user =newUser();
                user.setId(resultSet.getInt("id"));
                user.setUsername(resultSet.getString("username"));
                user.setPassword(resultSet.getString("password"));
                user.setPhone(resultSet.getString("phone"));System.out.println("登录成功"+ user.toString());}else{System.out.println("用户名或者密码错误");}}catch(Exception e){
            e.printStackTrace();}finally{JdbcUtil.release(resultSet, preparedStatement, connection);}return user;}@OverridepublicBooleanregister(User user){Connection connection =null;PreparedStatement preparedStatement =null;ResultSet resultSet =null;int result =0;try{
            connection =JdbcUtil.getConnection();String sql ="insert into user(username, password) values (?, ?);";
            preparedStatement = connection.prepareStatement(sql);
            preparedStatement.setString(1, user.getUsername());
            preparedStatement.setString(2, user.getPassword());
            result = preparedStatement.executeUpdate();}catch(Exception e){
            e.printStackTrace();}finally{JdbcUtil.release(resultSet, preparedStatement, connection);}// 三目表达式，result等1则人会true，否则返回falsereturn result ==1?true:false;}}

5.5 实现Servlet

1.LoginServlet

packageorg.javatop.case01.controller;importorg.javatop.case01.dao.UserDao;importorg.javatop.case01.dao.impl.UserDaoImpl;importorg.javatop.case01.domain.User;importjavax.servlet.ServletException;importjavax.servlet.annotation.WebServlet;importjavax.servlet.http.HttpServlet;importjavax.servlet.http.HttpServletRequest;importjavax.servlet.http.HttpServletResponse;importjava.io.IOException;/**
 * @author : Leo
 * @version 1.0
 * @date 2023-12-02 14:34
 * @description :
 */@WebServlet(name ="/login")publicclassLoginServletextendsHttpServlet{@OverrideprotectedvoiddoGet(HttpServletRequest request,HttpServletResponse response)throwsServletException,IOException{doPost(request,response);}@OverrideprotectedvoiddoPost(HttpServletRequest request,HttpServletResponse response)throwsServletException,IOException{

        request.setCharacterEncoding("UTF-8");
        response.setContentType("text/html;charset=UTF-8");// 获取前端页面传过来的值String username = request.getParameter("username");String password = request.getParameter("password");// 执行查询数据库逻辑UserDao userDao =newUserDaoImpl();User user = userDao.login(username, password);// 如果根据用户名和密码能查得到值if(user !=null){
            request.setAttribute("user", user);
            request.getRequestDispatcher("/success.jsp").forward(request, response);}else{// 用户名或者密码错误执行以下代码
            request.setAttribute("message","用户名或者密码错误");
            request.getRequestDispatcher("/defeat.jsp").forward(request, response);}}}

2.RegisterServlet

packageorg.javatop.case01.controller;importorg.javatop.case01.dao.UserDao;importorg.javatop.case01.dao.impl.UserDaoImpl;importorg.javatop.case01.domain.User;importjavax.servlet.ServletException;importjavax.servlet.annotation.WebServlet;importjavax.servlet.http.HttpServlet;importjavax.servlet.http.HttpServletRequest;importjavax.servlet.http.HttpServletResponse;importjava.io.IOException;/**
 * @author : Leo
 * @version 1.0
 * @date 2023-12-02 16:28
 * @description : 注册接口
 */@WebServlet(name ="/register")publicclassRegisterServletextendsHttpServlet{@OverrideprotectedvoiddoPost(HttpServletRequest req,HttpServletResponse resp)throwsServletException,IOException{doPut(req, resp);}@OverrideprotectedvoiddoPut(HttpServletRequest req,HttpServletResponse resp)throwsServletException,IOException{
        req.setCharacterEncoding("UTF-8");
        resp.setContentType("text/html;charset=UTF-8");String username = req.getParameter("username");String password = req.getParameter("password");User user =newUser();
        user.setUsername(username);
        user.setPassword(password);UserDao userDao =newUserDaoImpl();if(userDao.register(user)){System.out.println("注册成功");// 注册成功，跳转登录页面
            req.getRequestDispatcher("register-success.jsp").forward(req,resp);}else{System.out.println("注册失败");
            req.setAttribute("message","注册失败");
            req.getRequestDispatcher("register.jsp").forward(req,resp);}}}

5.6 编写数据库连接工具类

packageorg.javatop.case01.utils;importjava.sql.*;/**
 * @author : Leo
 * @version 1.0
 * @date 2023-11-28 20:59
 * @description : 数据库连接工具类
 */publicclassJdbcUtil{/**
     * 1、获取Connection
     * @return Connection
     * @throws Exception
     */publicstaticConnectiongetConnection()throwsException{Class.forName("com.mysql.cj.jdbc.Driver");returnDriverManager.getConnection("jdbc:mysql://localhost:3306/test","root","root");}/**
     * 2、释放资源
     * @param resultSet resultSet
     * @param statement statement
     * @param connection connection
     */publicstaticvoidrelease(ResultSet resultSet,Statement statement,Connection connection){if(resultSet !=null){try{
                resultSet.close();}catch(SQLException e){
                e.printStackTrace();}}if(statement !=null){try{
                statement.close();}catch(SQLException e){
                e.printStackTrace();}}if(connection !=null){try{
                connection.close();}catch(SQLException e){
                e.printStackTrace();}}}}

6.编写前端代码

这里为了演示效果我实现了两个简单的登录注册页面

6.1 登录页面

<%--
  Created by IntelliJ IDEA.
  User: Administrator
  Date: 2023/11/28
  Time: 20:52
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<!DOCTYPE html>
<html>
<head>
    <title>Login Page</title>
    <link rel="stylesheet" type="text/css" href="style.css">
</head>
<body>
<div class="form-container">
    <h2>登录</h2>
    <form action="/login" method="post">
        <input type="text" placeholder="Username" name="username" required>
        <input type="password" placeholder="Password" name="password" required>
        <button type="submit">Login</button>
        <a href="register.jsp">去注册</a>
    </form>
</div>
</body>
</html>

6.2 注册页面

<%--
  Created by IntelliJ IDEA.
  User: Administrator
  Date: 2023/11/28
  Time: 20:52
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<!DOCTYPE html>
<html>
<head>
    <title>Login Page</title>
    <link rel="stylesheet" type="text/css" href="style.css">
</head>
<body>
<div class="form-container">
    <h2>注册</h2>
    <form action="/register" method="post">
        <input type="text" placeholder="Username" name="username" required>
        <input type="password" placeholder="Password" name="password" required>
        <button type="submit">注册</button>
    </form>
</div>
</body>
</html>

6.3 登录错误页面

<%--
  Created by IntelliJ IDEA.
  User: Administrator
  Date: 2023/11/28
  Time: 21:10
  To change this template use File | Settings | File Templates.
--%>
<%--<%@ page contentType="text/html;charset=UTF-8" language="java"%>--%>
<%@ page contentType="text/html; charset=gb2312" language="java" %>
<html lang="en">
<head>
    <title>登录失败</title>
</head>
<body>
<h1>登录失败！</h1>
<font color="red">
    <%
        if(request.getAttribute("message")!= null){
            response.setContentType("text/html;charset=UTF-8");
            out.print(request.getAttribute("message"));
        }
    %>
</font>
<br>
<a href="login.jsp">重新登录</a>
</body>
</html>

6.4 登录成功页面

<%@ page import="org.javatop.case01.domain.User"%><%--Created by IntelliJIDEA.
  User:AdministratorDate:2023/11/28Time:21:10To change this template use File|Settings|FileTemplates.--%><%@ page contentType="text/html;charset=utf-8" language="java"%><html lang="en"><head><title>登录成功</title></head><body><h1>登录成功！</h1><br><font color="red"><%User user =(User)request.getAttribute("user");String username = user.getUsername();%>
    欢迎您：
    <%
        out.print(username);%></font></body></html>

6.5 注册成功页面

<%--Created by IntelliJIDEA.
  User:AdministratorDate:2023/11/28Time:21:10To change this template use File|Settings|FileTemplates.--%><%@ page contentType="text/html;charset=UTF-8" language="java"%><html lang="en"><head>ccccccccccccccccc
    <title>注册成功</title></head><body><h1>注册成功！</h1><br><a href="login.jsp">跳转登录</a><a href="register.jsp">继续注册</a></body>

7.总结

本篇教程内容比较长，适合初学者学习，但是也需要有一点基础，比如环境的配置，但如果你稍微有点基础，操作一下这篇文章是非常不错的，特别是代码。

8.最后总结

以上便是本文的全部内容，本人才疏学浅，文章有什么错误的地方，欢迎大佬们批评指正！我是Leo，一个在互联网行业的小白，立志成为更好的自己。

如果你想了解更多关于Leo，可以关注公众号-程序员Leo，后面文章会首先同步至公众号。

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标签： java servlet mysql

本文转载自: https://blog.csdn.net/qq_58608526/article/details/134757110
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